//animações de acordo com a altura do browser
var Animacoes = {
    icones: function(){
        var iconesNavigationOffsetTop = $('#icones').offset().top;
        var iconesNavigation = function() {
            var scroll_top = $(window).scrollTop();
            if (scroll_top > iconesNavigationOffsetTop) {
                $(".icones-1").animate({marginTop: "100px"}, "500");
                $('.icones-1').fadeTo("fast", 0.9, function() {
                    $(".icones-2").animate({marginTop: "100px"}, "500");
                    $('.icones-2').fadeTo("fast", 0.9, function() {
                        $(".icones-3").animate({marginTop: "100px"}, "500");
                        $('.icones-3').fadeTo("fast", 0.9);
                    });
                });

            }
        };
        iconesNavigation();
        $(window).scroll(function() {
            iconesNavigation();
        });
    }
};